Prompt for password when two step asks for app password

If we get a XML-RPC error 425, that means the password was correct, but
two step authentication is enabled, and we need to switch to an app
specific password
Added missing method
Fixed orientation parsing on iOS5
Fixes #1600.  Also fixes an issue where the user's password would disappear after scrolling the view in landscape orientation.
Adds a check for an uploading featured image when there are no other changes.
Fixes #1589.  Props mgcm.
Fixes #1588. Props mgcm.
Updated pods:

* Updated AFNetworking to 1.2
* Better error handling for WPXMLRPC and WordPressApi. refs #1622
Added Pods documentation to gitignore
Fixes #1594. Remove the delegate when leaving the view and restore it upon return.
Avoids coredata breakage when expected and actual row counts do not match.
Fixes #1622. Displays the relevant error in the case of a problem parsing.
Show a more helpful message if adding a blog fails due to server errors.
Refactor media uploading alert for featured images
Fix media upload error management
Better error management for uploads:

* Try to detect out of memory errors and show a relevant message
* Show an alert when uploads fail
Fixed help view controller

When there was a modal view present (e.g. error from the editor),
tapping on 'Need Help?' would do nothing.
Don't purge image files, unless the image already uploaded
Added unit tests for iOS5 rotation
Disabled unit tests for autosaves
Bump version to 3.5.3